Codility

get-largest-binary-gap.js

var trim = require("lodash/trim");
var max = require("lodash/max");

var dec2bin = function (dec){
    return (dec >>> 0).toString(2);
};

var getLargestBinaryGap = function(n){
    return max(
        trim(dec2bin(n), "0")
            .split("1")
            .map(function(a){
                return a.length;
            })
    );    
};